server.py

from flask import Flask, g, request, url_for, redirect, session, render_template, flash, Response
from werkzeug.routing import Rule
from functools import wraps
from datetime import date, timedelta, datetime, time, MINYEAR
import threading
import os
import hashlib
import random

app = Flask(__name__)

app.jinja_env.trim_blocks = True
app.jinja_env.lstrip_blocks = True

def timer_func():
	with app.test_request_context():
		pass # do something
	timer = threading.Timer(60*60, timer_func)
	timer.start()

timer = threading.Timer(0, timer_func)
timer.daemon = True
timer.start()

config = app.config
config['DB_SCHEMA'] = 'db_schema.sql'
config['DB_DATA'] = 'db_example.sql'
config['DB_ENGINE'] = 'sqlite'
config['SQLITE_DB'] = 'db.sqlite'
config['SQLITE_INIT_SCHEMA'] = True
config['SQLITE_INIT_DATA'] = False
config['DEBUG'] = False
config['VIDEOPREFIX'] = 'https://videoag.fsmpi.rwth-aachen.de'
if __name__ == '__main__':
	config['SQLITE_INIT_DATA'] = True
	config['DEBUG'] = True
config.from_pyfile('config.py', silent=True)
if config['DEBUG']:
	app.jinja_env.auto_reload = True

from db import query, searchquery, ldapauth, ldapget, convert_timestamp

mod_endpoints = []

@app.template_global()
def ismod(*args):
	return ('user' in session)

def mod_required(func):
	mod_endpoints.append(func.__name__)
	@wraps(func)
	def decorator(*args, **kwargs):
		if not ismod():
			flash('Diese Funktion ist nur für Moderatoren verfügbar!')
			return redirect(url_for('login', ref=request.url))
		else:
			return func(*args, **kwargs)
	return decorator

app.jinja_env.globals['navbar'] = []
def register_navbar(name, icon=None):
	def wrapper(func):
		endpoint = func.__name__
		app.jinja_env.globals['navbar'].append((endpoint, name, icon,
					not endpoint in mod_endpoints))
		return func
	return wrapper

def render_endpoint(endpoint, flashtext=None, **kargs):
	if flashtext:
		flash(flashtext)
	# request.endpoint is used for navbar highlighting
	request.url_rule = Rule(request.path, endpoint=endpoint)
	return app.view_functions[endpoint](**kargs)

def handle_errors(endpoint, text, code, *errors, **epargs):
	def wrapper(func):
		@wraps(func)
		def decorator(*args, **kwargs):
			try:
				return func(*args, **kwargs)
			except errors:
				if endpoint:
					return render_endpoint(endpoint, text, **epargs), code
				else:
					return text, code
		return decorator
	return wrapper

@app.errorhandler(404)
def handle_not_found(e):
	return render_endpoint('index', 'Diese Seite existiert nicht!'), 404

@app.template_filter(name='semester')
def human_semester(s, long=False):
	if not s or s == 'zeitlos' or len(s) != 6:
		return 'Zeitlos'
	year = s[0:4]
	semester = s[4:6].upper()
	if not year.isdigit() or semester not in ['SS', 'WS']:
		print('Invalid semester string "%s"'%s)
		return '??'
	if not long:
		return semester+year[2:]
	elif semester == 'SS':
		return 'Sommersemester %s'%year
	else:
		return 'Wintersemester %s/%s'%(year, str(int(year)+1)[2:])

@app.template_filter(name='date')
def human_date(d):
	return d.strftime('%d.%m.%Y')

@app.template_filter()
def rfc3339(d):
	return d.strftime('%Y-%m-%dT%H:%M:%S+02:00')

@app.route('/')
@register_navbar('Home', icon='home')
def index():
	return render_template('index.html', latestvideos=query('''
				SELECT lectures.*, max(videos.time_updated) AS lastvidtime, courses.short, courses.downloadable, courses.title AS coursetitle
				FROM lectures
				LEFT JOIN videos ON (videos.lecture_id = lectures.id)
				LEFT JOIN courses on (courses.id = lectures.course_id)
				WHERE (? OR (courses.visible AND courses.listed AND lectures.visible AND videos.visible))
				GROUP BY videos.lecture_id
				ORDER BY lastvidtime DESC
				LIMIT 6
			''', ismod()))

@app.route('/course')
@register_navbar('Videos', icon='film')
def courses():
	courses = query('SELECT * FROM courses WHERE (? OR (visible AND listed))', ismod())
	for course in courses:
		if course['semester'] == '':
			course['semester'] = 'zeitlos'
	groupedby = request.args.get('groupedby')
	if groupedby not in ['title', 'semester', 'organizer']:
		groupedby = 'semester'
	return render_template('courses.html', courses=courses, groupedby=groupedby)

@app.route('/course/<handle>')
@app.route('/course/<int:id>')
@handle_errors('courses', 'Diese Veranstaltung existiert nicht!', 404, IndexError)
def course(id=None, handle=None):
	if id:
		courses = query('SELECT * FROM courses WHERE id = ? AND (? OR visible)', id, ismod())[0]
	else:
		courses = query('SELECT * FROM courses WHERE handle = ? AND (? OR visible)', handle, ismod())[0]
	lectures = query('SELECT * FROM lectures WHERE course_id = ? AND (? OR visible)', courses['id'], ismod())
	videos = query('''
			SELECT videos.*, (videos.downloadable AND courses.downloadable) as downloadable, formats.description AS format_description
			FROM videos
			JOIN lectures ON (videos.lecture_id = lectures.id)
			JOIN formats ON (videos.video_format = formats.id)
			JOIN courses ON (lectures.course_id = courses.id)
			WHERE lectures.course_id= ? AND (? OR videos.visible)
			ORDER BY lectures.time, formats.prio DESC
			''', courses['id'], ismod())
	return render_template('course.html', course=courses, lectures=lectures, videos=videos)

@app.route('/faq')
@register_navbar('FAQ', icon='question-sign')
def faq():
	return render_template('faq.html')

@app.route('/play/<int:id>')
@handle_errors('course', 'Diese Vorlesung existiert nicht!', 404, IndexError)
def lecture(id):
	lectures = query('SELECT * FROM lectures WHERE id = ? AND (? OR visible)', id, ismod())
	videos = query('SELECT videos.*, formats.description AS format_description FROM videos JOIN formats ON (videos.video_format = formats.id) WHERE lecture_id = ? AND (? OR visible)', id, ismod())
	if not videos:
		flash('Zu dieser Vorlesung wurden noch keine Videos veröffentlicht!')
	courses = query('SELECT * FROM courses WHERE id = ? AND (? OR (visible AND listed))', lectures[0]['course_id'], ismod())
	if not courses:
		return render_endpoint('course', 'Diese Veranstaltung existiert nicht!'), 404
	chapters = query('SELECT * FROM chapters WHERE lecture_id = ? AND NOT deleted AND (? OR visible) ORDER BY time ASC', id, ismod())
	return render_template('lecture.html', course=courses[0], lecture=lectures[0], videos=videos, chapters=chapters)

@app.route('/search')
def search():
	if 'q' not in request.args:
		return redirect(url_for('index'))
	q = request.args['q']
	courses = searchquery(q, '*', ['title', 'short', 'organizer', 'subject', 'description'],
			'courses', 'WHERE (? OR (visible AND listed)) GROUP BY id ORDER BY _score DESC, semester DESC LIMIT 20', ismod())
	lectures = searchquery(q, 'lectures.*, courses.visible AS coursevisible, courses.listed, courses.short, courses.downloadable, courses.title AS coursetitle',
			['lectures.title', 'lectures.comment', 'lectures.speaker', 'courses.short'],
			'lectures LEFT JOIN courses on (courses.id = lectures.course_id)',
			'WHERE (? OR (coursevisible AND listed AND visible)) GROUP BY id ORDER BY _score DESC, time DESC LIMIT 30', ismod())
	return render_template('search.html', searchtext=request.args['q'], courses=courses, lectures=lectures)

def check_mod(user, groups):
	return user and 'users' in groups

@app.route('/login', methods=['GET', 'POST'])
def login():
	if request.method == 'GET':
		return render_template('login.html')
	user, groups = ldapauth(request.form.get('user'), request.form.get('password'))
	if not check_mod(user, groups):
		flash('Login fehlgeschlagen!')
		return render_template('login.html')
	session['user'] = ldapget(user)
	dbuser = query('SELECT * FROM users WHERE name = ?', user)
	if not dbuser:
		query('INSERT INTO users (name, realname, fsacc, level, calendar_key, rfc6238) VALUES (?, ?, ?, 1, "", "")', user, session['user']['givenName'], user)
		dbuser = query('SELECT * FROM users WHERE name = ?', user)
	session['user']['dbid'] = dbuser[0]['id']
	return redirect(request.values.get('ref', url_for('index')))

@app.route('/logout', methods=['GET', 'POST'])
def logout():
	session.pop('user')
	return redirect(request.values.get('ref', url_for('index')))

@app.route('/edit', methods=['GET', 'POST'])
@mod_required
def edit(prefix="", ignore=[]):
	# All editable tables are expected to have a 'time_updated' field
	tabs = {
		'courses': ('courses_data', 'id', ['visible', 'listed', 'title', 'short',
				'handle', 'organizer', 'subject', 'semester', 'downloadable',
				'internal', 'responsible','deleted']),
		'lectures': ('lectures_data', 'id', ['visible', 'title', 'comment',
				'internal', 'speaker', 'place', 'time', 'duration', 'jumplist','deleted']),
		'videos': ('videos_data', 'id', ['visible','deleted']),
		'chapters': ('chapters', 'id', ['time', 'text', 'visible', 'deleted'])
	}
	query('BEGIN')
	if request.is_json:
		changes = request.get_json().items()
	else:
		changes = request.args.items()
	for key, val in changes:
		if key in ignore:
			continue
		key = prefix+key
		table, id, column = key.split('.', 2)
		assert table in tabs
		assert column in tabs[table][2]
		query('INSERT INTO changelog ("table",id_value,id_key,field,value_new,value_old,"when",who,executed) VALUES (?,?,?,?,?,(SELECT %s FROM %s WHERE %s = ?),?,?,1)'%(column,tabs[table][0],tabs[table][1]),table,id,tabs[table][1],column,val,id,datetime.now(),session['user']['givenName'])
		query('UPDATE %s SET %s = ?, time_updated = ? WHERE %s = ?'%(tabs[table][0], column, tabs[table][1]), val, datetime.now(), id)
	query('COMMIT')
	return "OK", 200

@app.route('/newcourse', methods=['GET', 'POST'])
@mod_required
def new_course():
	id = query('''
		INSERT INTO courses_data
			(visible, title, short, handle, organizer, subject, created_by, time_created,
			 time_updated, semester, settings, description, internal, responsible, feed_url)
			VALUES (0, "Neue Veranstaltung", "Neu", ?, "", "", ?, ?, ?, "", "", "", "", ?, "")
		''', 'new'+str(random.randint(0,1000)), session['user']['dbid'], datetime.now(), datetime.now(),
		session['user']['givenName'])
	edit(prefix='courses.'+str(id)+'.', ignore=['ref'])
	if 'ref' in request.values:
		return redirect(request.values['ref'])
	return str(id), 200

@app.route('/newlecture/<courseid>', methods=['GET', 'POST'])
@mod_required
def new_lecture(courseid):
	id = query('''
		INSERT INTO lectures_data
			(course_id, visible, drehplan, title, comment, internal, speaker, place,
				time, time_created, time_updated, jumplist, titlefile)
			VALUES (?, 0, "", "Noch kein Titel", "", "", "", "", ?, ?, ?, "", "")
		''', courseid, datetime.now(), datetime.now(), datetime.now())
	edit(prefix='lectures.'+str(id)+'.', ignore=['ref'])
	if 'ref' in request.values:
		return redirect(request.values['ref'])
	return str(id), 200

@app.route('/auth')
def auth(): # For use with nginx auth_request
	if 'X-Original-Uri' not in request.headers:
		return 'Internal Server Error', 500
	url = request.headers['X-Original-Uri'].lstrip(config['VIDEOPREFIX'])
	ip = request.headers.get('X-Real-IP', '')
	if url.endswith('jpg'):
		return "OK", 200
	videos = query('''SELECT videos.path, videos.id, lectures.id AS lecture_id, courses.id AS course_id, auth.*
      FROM videos
      JOIN lectures ON (videos.lecture_id = lectures.id)
      JOIN courses ON (lectures.course_id = courses.id)
			LEFT JOIN auth ON (videos.id = auth.video_id OR lectures.id = auth.lecture_id OR courses.id = auth.course_id)
      WHERE videos.path = ?
      AND (? OR (courses.visible AND lectures.visible AND videos.visible))
			ORDER BY auth.video_id DESC, auth.lecture_id DESC, auth.course_id DESC''',
			url, ismod())
	if not videos:
		return "Not allowed", 403
	allowed = False
	types = []
	auth = request.authorization
	for video in videos:
		if videos[0] and ((videos[0]['video_id'] and not video['video_id']) \
				or (videos[0]['lecture_id'] and not video['lecture_id'])):
			break
		types.append(video['auth_type'])
		if video['auth_type'] == 'public':
			allowed = True
			break
		elif video['auth_type'] == 'password':
			if auth and video['auth_user'] == auth.username and video['auth_passwd'] == auth.password:
				allowed = True
				break
	if not types[0] or allowed or ismod() or \
			(auth and check_mod(*ldapauth(auth.username, auth.password))):
		return 'OK', 200
		query('INSERT INTO log VALUES (?, "", ?, "video", ?, ?)', ip, datetime.now(), videos[0]['id'], url)
	elif 'password' in types:
		return Response("Login required", 401, {'WWW-Authenticate': 'Basic realm="Login Required"'})
	return "Not allowed", 403

@app.route('/schedule')
@register_navbar('Drehplan', 'calendar')
@mod_required
def schedule():
	if 'kw' not in request.args:
		kw=0
	else:
		kw=int(request.args['kw'])
	start = date.today() - timedelta(days=date.today().weekday() -7*kw)
	days = [{'date': start, 'lectures': [], 'atonce':0, 'index': 0 }]
	earlieststart=time(23,59)
	latestend=time(0,0)
	for i in range(1,7):
		days.append({'date': days[i-1]['date'] + timedelta(days=1), 'atonce':0, 'index': i, 'lectures':[] })
	for i in days:
		# date and times are burning in sqlite
		s = datetime.combine(i['date'],time())
		e = datetime.combine(i['date'],time(23,59))
		i['lectures'] = query ('''
					SELECT lectures.*,courses.short
					FROM lectures 
					JOIN courses ON (lectures.course_id = courses.id) 
					WHERE (time < ?) AND (time > ?) 
					ORDER BY time ASC'''
				,e,s);
		# sweepline to find out how many lectures overlap
		maxcol=0;
		curcol=0;
		freecol=[];
		for l in i['lectures']:
			# who the hell inserts lectures with zero length?!?!?
			l['time_end'] = l['time']+timedelta(minutes=max(l['duration'],1))
		for l in sorted([(l['time'],True,l) for l in i['lectures']] + [(l['time_end'],False,l) for l in i['lectures']],key=lambda t:(t[0],t[1])):
			if l[1]:
				curcol += 1
				if curcol > maxcol:
					maxcol = curcol
				if len(freecol) == 0:
					freecol.append(maxcol)
				l[2]['schedule_col'] = freecol.pop()
				if earlieststart > l[0].time():
					earlieststart = l[0].time()
			else:
				curcol -= 1
				freecol.append(l[2]['schedule_col'])
				if latestend < l[0].time():
					latestend = l[0].time()
		i['maxcol'] = max(maxcol,1)
	times=[]
	s = min(earlieststart,time(8,0))
	e = max(latestend,time(19,0))
	for i in range(s.hour*4,min(int((60*e.hour/15)/4)*4+5,24*4)):
		t = i*15
		times.append(time(int(t/60),t%60))
	return render_template('schedule.html',days=days,times=times,kw=kw)

@app.route('/stats')
@register_navbar('Statistiken', 'stats')
@mod_required
def stats():
	return render_template('stats.html')

@app.route('/log')
@register_navbar('Changelog', 'book')
@mod_required
def changelog():
	changelog = query('SELECT *, ( "table" || "." || id_value || "." ||field) as path FROM changelog LEFT JOIN users ON (changelog.who = users.id) ORDER BY "when" DESC LIMIT 50')
	return render_template('changelog.html', changelog=changelog)

@app.route('/files/<filename>')
def files(filename):
	return redirect(config['VIDEOPREFIX']+'/'+filename)

@app.route('/newchapter/<int:lectureid>', methods=['POST', 'GET'])
def suggest_chapter(lectureid):
	time = request.values['time']
	text = request.values['text']
	assert(time and text)
	time = int(time)
	submitter = None
	if not ismod():
		submitter = request.environ['REMOTE_ADDR']
	id = query('INSERT INTO chapters (lecture_id, time, text, time_created, time_updated, created_by, submitted_by) VALUES (?, ?, ?, ?, ?, ?, ?)',
				lectureid, time, text, datetime.now(), datetime.now(), session.get('user', {'dbid':None})['dbid'], submitter)
	if 'ref' in request.values:
		return redirect(request.values['ref'])
	return 'OK',  200

import feeds
import importer